Draft gear for railway draft rigging



y 1959 H. w. MULCAHY 2,893,570

DRA'FT GEAR FOR, RAILWAY DRAFT RIGGING Filed July 3, 1956 2 Sheets-Sheet 1 Invenior Harry WMuZcahy July 7, 1959 H. w. MULCAHY 2,393,570

7 DRAFT GEAR FOR RAILWAY DRAFT RIGGING Filed July 3; 1956 2 Sheets-Sheet 2 I n ve nior Harry W Mulcah Patented July 7, 1959 1 2,893,570 DRAFT GEAR FOR RAILWAY DRAFT RIGGING Harry W. Mulcahy, Chicago, ]l l.,'assignor to W. H. Miner, Inc., Chicago, 111., a corporation of Delaware Application July 3, 1956, Serial No. 595,656

4 Claims. (Cl. 213-'-44) This invention relates to draft gear for railway draft rigging and particularly to draft gear having rubber ele ments which are stressed primarily in shear.

It is a main object of the invention to provide a rubber draft gear for railway draft rigging, wherein the rubber is stressed mainly in shear during operations of the gear and in which the plates to which the rubber :units are bonded are corrugated toresistbe nding forces exerted upon the plates during operation of the gear.

Another object of the invention is to'provide a resilient unit having'stifieners within or on the plates which are longitudinally offset and have a rubber mass bonded therebetween, which stiifeners prevent distortion and permanent bending of the free ends of the plates during compression thereof and thus permit the use of lighter plates for the same capacity as can be obtained with thicker but non-stiffened plates.

Further objects of the invention not specifically mentioned will be apparent from the detailed description and claims which follow, reference being made to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which:

Figure 1 is a cut-away perspective view of the gear in assembled condition.

Figure 2 is a cross sectional view of the gear taken along the line 2--2 of Figure 1.

Figure 3 is a view in perspective of a preferred form of locking plate for the gear.

Co-pending application, Serial No. 581,101, filed April 27, 1956, provides a rubber draft gear employing a small number of parts and in which the rubber is stressed mainly in shear by operations of the gear. The present invention is an improvement over that general type of gear show-n in said co-pending application in the provision of undulations or stiffening sections serving to rigidify the free ends of those plate members which are bonded to the rubber elements. Describing the draft gear of the instant invention in detail, it will be noted that the gear consists of a plurality of rubber units A disposed side by side and extending longitudinally of the gear, a front end cap B enclosing the ends of the units A, a similar rear end cap C, and a pair of locking plates D serving to interconnect the caps B and C.

Each rubber unit A consists of a pair of metal plates and 11 disposed parallel to each other and longi tudinally offset one with respect to the other and a \mass of rubber 12 disposed between and bonded to the adjacent faces of plates 10 and 11. The plates 10 and 11 are rectangular in shape and adapted to be disposed with their longer edges extending longitudinally of the gear.

The front end cap B consists of a front wall 15, rearwardly extending side walls, side wall 16 being visible in part in Figure 1, a top wall 18 and a bottom wall (not visible). The side walls are each provided with a generally rectangular slot 20.

The rear cap C is of similar construction, consisting of a rear wall (not visible), forwardly extending side walls 22 and 23, a top wall 24 and a bottom wall 25, all integrally joined together. Side walls 22 and 23 contain slots 26 which, though generally rectangular in shape, have rounded end portions 27 and are shorter longitudinally of the gear than the corresponding dimension of slots 20 in the front cap B.

The locking plates D each consist of a rectangular metal plate 28 at the front end of which is a lug 29, the forward end of which is beveled as indicated at 30. A lug 31, corresponding in configuration to the slots 26, is disposed at the rear end of the plate 28.

As clearly shown in Figure 2, the plates 10 and '11 have stiffener elements in the form of corrugations 32 and 33, respectively, which are complementary so that the plates are in contact with each other throughout their entire adjacent' surfaces. As shown in Figure l, the corrugations 32 and 33 extend longitudinally of the gear and substantially parallel to the longitudinal axis thereof. If desired, the stiffener elements may take the form of integral ribs extending from the plates 10 or 11 inwardly into the rubber'mass 12. Although notillustrated, the stiffener elements may be disposed at any angle up, to 45 degrees relative to the longitudinal axis of the gear. Of course, longitudinally extending corrugations are preferred but mention is made of the inclined or diagonally extending stiffener elements, or the use of integral ribs, to indicate that the same need not be exactly parallel to the longitudinal axis of the gear nor need be in the form of corrugations. Similarly, the locking mechanism described is the preferred form although it is appreciated that other locking mechanisms can be employed if desirable.

To assemble the gear the rear cap C is placed open end uppermost and the locking plates D are then placed within the cap C so that the lugs 31 register in the slots 26 in which said lugs snugly fit. Resilient units A are next placed in the cap between the plates D. It will 'be noted that alternate units A are so placed within the rear cap C that certain contacting plates 10 and 11, as Well as the outermost plates 10 and 11, abut against the inner surface of the rear wall of the rear cap C, whereas the intervening plates 10 and 11 project upwardly from the upper surfaces of the rubber 12 in units A. The front cap B is then placed over the upper ends of units A and forced downwardly. The rear ends 34 of the side walls, such as 16, of the front cap B will now be positioned lowermost and will engage the bevels 30 on the locking plates D, forcing those plates inwardly to permit the lugs 29 to pass between the side walls. The masses of rubber 12 in units A are thus compressed. When the front wall 15 is engaged by the ends of upstanding plates 10 and 11, further movement of the front cap B stresses the rubber 12 to build up an initial resistance therein. When the cap B has been moved far enough to register lugs 29 with the slots 20, the rubber in units A expand and force the lugs into said slots to complete assembly of the gear.

In operation of the gear, the front cap B moves rearwardly toward the rear cap C, stressing the rubber units A in shear. When the gear goes solid the rear surfaces 34 of front cap B will be in abutting relation with the front surfaces 35 of the rear cap C. At this time the free ends of plates 10 and 11, that is, those ends which are spaced from the inner surfaces of front and rear walls of the respective end caps, will still be spaced away from said surfaces, although to a lesser extent, and the rubber masses 12 will be exerting a tension force tending to bend the free end and pull same into closer proximity to the plate bonded to the other face of the same rubber mass. The corrugations or stiffener sections 32 and 33 resist such tension forces and prevent the free ends of the plates from being permanently bent or deformed.

Having thus complied with the statutes and shown and described a preferred embodiment of my invention,.

what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What I claim is:

1. A rubber unit for a draft gear, consisting of a rubber mass disposed between and bonded to a pair of longitudinally ofiset, parallel, corrugated plates, such corrugations extending longitudinally of the plates.

2. A rubber unit for a draft gear, consisting of a rubber mass disposed between and bonded to a pair of Iongitudinally offset, parallel plates having stiffener elements extending substantially longitudinally of the plates.

3. A draft gear for railway draft rigging, wherein rubber is stressed mainly in shear during operation of the gear, comprising: a resilient column consisting of a plurality of pairs of rectangular plates and single outer plates disposed parallel to each other and extending longitudinally of the gear, alternate pairs of the plates and the single outer plates being oifset longitudinally with respect to the intervening pairs of plates, the plates having stifiener sections extending longitudinally of the gear; a pad of rubber interposed between adjacent pairs of plates and bonded to one plate of each pair; a pad of rubber interposed between each outer pair of plates and each .singleouter plate and bonded thereto; a rear cap against the inner face of which said alternate pairs of plates and the single outer plates abut; a front cap against the inner face of which the said intervening pairs of plates abut; a pair of locking plates disposed one on each side of the column, a lug projecting outwardly from each end of each of the locking plates with the lugs on the rear ends of such plates being receivable in slots in the side walls of the rear cap, and the lugs on the front ends of the locking plates being receivable in longitudinally elongated slots in the side walls of the front cap.

4. A draft gear according to claim 3 in which the stiffener sections of each plate comprise spaced, longitudinally extending indentations which in pairs of contacting plates are complementary to each other.

References Cited in the file of this patent UNITED STATES PATENTS 

